Positive drive



Jan. 12 1926.. 1,569,044

G. D. SMITH r:r AL

POSITIVE DRIVE Filed August 23, 1924 2 Shasta-Sheet 1 B an m Sn 5 am a Jan. 12 1926.

Filed August 23. 1 924 2 Sheets-Sheet 2 Patented Jan. 12, 1926.

I meant GLENN D. SMITH AND WILBUB E.

EARHARZ, OF PONTIAC, MIGIIIGAN.

POSITIVE DRIVE.

Application filed To all whom wet/y concern."

Be it known that we, GLENN 1). SMITH and lViLBUn l3. EARHAR'r, citizens of the United States, residing at Pontiac, in the county of Oakland and State of lliiiohigan, have invented certain new and useful Improvements in Positive Drives, of which the followingis a specification.

The present invention relates to improvements in differentials and aims to provide a device of this nature whereby a positive drive is provided. The present modification of the invention is designed particularly for use upon automobiles for the purpose of preventing one wheel from spinning or the like thereby eliminating all inconveniences and danger occasioned by said spinning.

Another very important object of the invention to provide a differential structure which is simple and efficient, one which is reliable and positive in action, inexpensire to manufacture, strong, durable, and well adapted to the purpose for which it is designed.

With the above and numerous other objects in view as will appear as the descrip tion progresses, the invention resides in certain novel features of construction and in the combination and arrangement of parts as will be hereinafter more fully described and claimed.

In the drawing:

Figure 1 is a sectional. view through the structure forming our invention, a

Figure 2 is a transverse section therethrough taken substantially on the line 2-2 of Figure 1 looking in the direction of the arrows,

Figure 3 is a. similar section taken on the line 3-3 of Figure 1 looking in the direction of the arrows.

Figure 4: is a detail perspective view of one of the blocks used in conjunction with the differential, and

Figure 5 is a detail perspective of one of the wedge rollers used with this differential.

Referring to the drawing in detail it will be seen that the particular differential housing 1 herein illustrated is substantially cylindrical in formation and is closed by end plates 2 held in place by bolts 3 or in any other suitable manner. An external annular flange 4 is provided on the outside of the housin 1 to which is attached the ring gear 5 which may be of any desired conventional August 23, 1924.. seen no. 733,822.

form and is here shown rivets or bolts 6.

Two partitions 8 are formed in the hous- 1 equidistant from the plates 2 so as to form a central compartment 9 and end compartments 10. The differential spider structure is mounted in the center compartment and. includes the differential pinions 11 rotatably carried by the housing and meshing with the two differential gears 12 keyed on the axles l3. These axles 18 extend through the plates 2 and the'partitions 8.

On each axle 13 within the respective compartment there is mounted a cam block 14;. These blocks 14, as is illustrated to advantage inv Figures 3 and 4 are provided with two oppositely disposed cam faces 15 and two oppositely disposed extensions 16. A roller 17 is disposed within the confines of the extension 16 on each cam surface 15. lVhen the rollers 17 are positioned as is shown at the bottom of Figure 3 they do not interfere with the action of the block and the housing but when the roller 17 is positioned as shown in-the upper portion of Figure 3 it is wedged between. the housing and the block keying them together for rotation with each other. Each block is keyed to its respective axle as is indicated at 18.

From the above detailed. description of the parts of the differential mechanism it is thought that a clear understanding of its operation may be obtained. In order, however, to aid in the understanding of the operation of the differential the following example is set forth in detail.

Considering the disclosure in Figure 1 and presuming that the left hand axle 13 is spinning while the right hand axle 13 is running at proper speed while the vehicle is moving forwardly. Under these circum stances it will be seen that the block 14. to the left of the figure will be rotating at a faster rate of speed than the housing thereby drawing or positioning one of the rollers 17, depending upon the direction of travel of the vehicle toward the end of the cam surface closer to the housing thereby wedging the roller betweenthe block and the housing and preventing further spinning of the left hand shaft so that the power will be imparted to the right hand shaft and the vehicle continue uninterrupted on its forward journey. It is very evident to those skilled in the art this invention will elimias held in place by i nate the nuisance of having one wheel spinning in a mud hole or the like and will to a great extent eliminate skidding which is often caused by the spinning of one wheel on a slipperyportionof a street. The portions of the cam surfaces l5 of each block which are closest to the housing are adjacent each other as is evident from an inspection of Figure 3 so that the differential acts positively while it is being operated to propel the'vehicle forwardly or rearwardly.

The particular difierential which we have illustrated and described in detail has been designed primarily for use with Ford automobiles but, of course, it is evident that it is well within the scope of-a skilled mechanic to make such changes as may be necessary to adapt the invention to other makes of automobiles. It is also desired to point out that numerous changes in the details of construction, and in the combination and arrangement of arts may be resorted to with departing f fom the spirit or scope of the invention as hereinafter claimed or sacrificing any of itsadvantages.

Having thus described our invention what we claim as new is:

1. In a differential mechanism of the class described, a differential housing, a gear on the exterior of the differential housing, a pair of partitions disposed in spaced relation to each other within the housing to form a central compartment and two end compartments, axles extending into the housing and terminating within the central compartment, differential gears on the inner end of the axles, a differential spider mechanism within the central compartment and mounted on the housing and in cooperative association with the differential gears, a'block keyed to each axle and disposed within the corresponding end compartments and provided with a pair of oppositely disposed cam surfaces, and rollers on the cam surfaces adapted to be wedged therebetween and the housing upon the spinning of the associated axle allin the manner and for the purpose specified.

2. In a power transmission mechanism, the combination of a divided shaft, differential gearing connecting the opposing ends of the divided shaft, a two way clutch member fixed to each portion of the divided shaft, a rotatable housing in operative engagement with the differential gearing, said housing having its opposite ends suitably formed to constitute members of clutches for two way power transmitting engagement with the clutch members fixed to the respective portions of the divided shaft, a plurality of rollers between the members of the respective clutches, and means to rotate the housing.

3. In a power transmission mechanism, the combination of a divided shaft differential gearing connecting the opposing ends of the divided shaft, a rotatable housing in operative relation with the differential gearing, and a plurality of two way clutches each comprising a member fixed to one part of the divided shaft .and an adjacent end of the rotatable housing constituting the other clutch member, and rollers disposed between the members of the respective clutches to cause the shaft and the housing to rotate together in both directions and to permit either shaft to instantly disengage from the rotatable housing without manual effort and rotate faster in both directions than the housing.

In testimony whereof we affix our signatures.

GLENN D. SMITH. WILBUR F. EARHART. 

